Endodontic sealants are used to seal portions of dental roots and are often used for root canal treatment. In order to be effective, endodontic sealants should be non-toxic to the patient and biocompatible with surrounding tissue, tooth, and bone. Many clinical applications of endodontic sealant exist in endodontic and pedodontic practice. Uses of endodontic sealant for tooth root treatment include, for example, sealing of perforations, furcation repair, pulp capping, apexification, repairing root that is damaged during a root canal procedure, and treating root resorption. Endodontic sealants may also be used as retrograde filling materials or pulpotomy agents.
Biodegradable dental compositions are often used as bone replacement materials, such as bone grafts, because the compositions degrade and allow new bone or other tissue to substantially replace the composition. For example, U.S. Pat. No. 6,787,584 discloses a degradable dental composition which is intended to interact with surrounding tissues to promote re-growth of tissue and bone. For endodontic sealants, however, biodegradability is a disadvantage. Rather, one of the main purposes of endodontic sealants is to provide a lasting seal which remains in place and is not re-absorbed by the body. Non-biodegradability ensures that the affected area remains sealed off from surrounding tissue, tooth, and bone. One of the advantages of non-biodegradability, for example, is that bacteria and other infectious organisms are prevented from migrating into the root canal cavity or from the root canal into bone.
Efforts have been made to provide endodontic sealants which are non-biodegradable. For example, ProRoot® MTA (Mineral Trioxide Aggregate), sold by Dentsply, is used as a non-biodegradable endodontic sealant. In its clinical application, the MTA powder is mixed with water to provide a grainy mixture, and is then delivered and gently packed into the desired area. MTA is biocompatible and provides an effective sealant for tooth roots. However, MTA requires moisture to solidify or set, with setting times varying from approximately 3.5 hours to approximately 5 hours. Due to the long setting time, post-operative bleeding may cause portions of the sealant to be lost from the site of application. Also, in applications where a moist cotton pellet is placed on top of the MTA to ensure proper setting, a second treatment is required to remove the pellet, thus causing discomfort and inconvenience for the patient. Accordingly, it is desirable to provide an endodontic sealant that is non-biodegradable and requires a shorter setting time for the sealant to solidify.